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## This file is part of Scapy
## See http://www.secdev.org/projects/scapy for more informations
## Copyright (C) Philippe Biondi <phil@secdev.org>
## This program is published under a GPLv2 license
"""
Linux specific functions.
"""
from __future__ import with_statement
import sys,os,struct,socket,time
from select import select
from fcntl import ioctl
import scapy.utils
import scapy.utils6
from scapy.config import conf
from scapy.data import *
from scapy.supersocket import SuperSocket
import scapy.arch
from scapy.error import warning, Scapy_Exception
# From bits/ioctls.h
SIOCGIFHWADDR = 0x8927 # Get hardware address
SIOCGIFADDR = 0x8915 # get PA address
SIOCGIFNETMASK = 0x891b # get network PA mask
SIOCGIFNAME = 0x8910 # get iface name
SIOCSIFLINK = 0x8911 # set iface channel
SIOCGIFCONF = 0x8912 # get iface list
SIOCGIFFLAGS = 0x8913 # get flags
SIOCSIFFLAGS = 0x8914 # set flags
SIOCGIFINDEX = 0x8933 # name -> if_index mapping
SIOCGIFCOUNT = 0x8938 # get number of devices
SIOCGSTAMP = 0x8906 # get packet timestamp (as a timeval)
# From if.h
IFF_UP = 0x1 # Interface is up.
IFF_BROADCAST = 0x2 # Broadcast address valid.
IFF_DEBUG = 0x4 # Turn on debugging.
IFF_LOOPBACK = 0x8 # Is a loopback net.
IFF_POINTOPOINT = 0x10 # Interface is point-to-point link.
IFF_NOTRAILERS = 0x20 # Avoid use of trailers.
IFF_RUNNING = 0x40 # Resources allocated.
IFF_NOARP = 0x80 # No address resolution protocol.
IFF_PROMISC = 0x100 # Receive all packets.
# From netpacket/packet.h
PACKET_ADD_MEMBERSHIP = 1
PACKET_DROP_MEMBERSHIP = 2
PACKET_RECV_OUTPUT = 3
PACKET_RX_RING = 5
PACKET_STATISTICS = 6
PACKET_MR_MULTICAST = 0
PACKET_MR_PROMISC = 1
PACKET_MR_ALLMULTI = 2
# From bits/socket.h
SOL_PACKET = 263
# From asm/socket.h
SO_ATTACH_FILTER = 26
SOL_SOCKET = 1
# From net/route.h
RTF_UP = 0x0001 # Route usable
RTF_REJECT = 0x0200
LOOPBACK_NAME="lo"
with os.popen("tcpdump -V 2> /dev/null") as _f:
if _f.close() >> 8 == 0x7f:
log_loading.warning("Failed to execute tcpdump. Check it is installed and in the PATH")
TCPDUMP=0
else:
TCPDUMP=1
del(_f)
def get_if_raw_hwaddr(iff):
return struct.unpack("16xh6s8x",get_if(iff,SIOCGIFHWADDR))
def get_if_raw_addr(iff):
try:
return get_if(iff, SIOCGIFADDR)[20:24]
except IOError:
return "\0\0\0\0"
def get_if_list():
try:
f=open("/proc/net/dev","r")
except IOError:
warning("Can't open /proc/net/dev !")
return []
lst = []
f.readline()
f.readline()
for l in f:
lst.append(l.split(":")[0].strip())
return lst
def get_working_if():
for i in get_if_list():
if i == LOOPBACK_NAME:
continue
ifflags = struct.unpack("16xH14x",get_if(i,SIOCGIFFLAGS))[0]
if ifflags & IFF_UP:
return i
return LOOPBACK_NAME
def attach_filter(s, filter):
# XXX We generate the filter on the interface conf.iface
# because tcpdump open the "any" interface and ppp interfaces
# in cooked mode. As we use them in raw mode, the filter will not
# work... one solution could be to use "any" interface and translate
# the filter from cooked mode to raw mode
# mode
if not TCPDUMP:
return
try:
f = os.popen("%s -i %s -ddd -s 1600 '%s'" % (conf.prog.tcpdump,conf.iface,filter))
except OSError,msg:
log_interactive.warning("Failed to execute tcpdump: (%s)")
return
lines = f.readlines()
if f.close():
raise Scapy_Exception("Filter parse error")
nb = int(lines[0])
bpf = ""
for l in lines[1:]:
bpf += struct.pack("HBBI",*map(long,l.split()))
# XXX. Argl! We need to give the kernel a pointer on the BPF,
# python object header seems to be 20 bytes. 36 bytes for x86 64bits arch.
if scapy.arch.X86_64:
bpfh = struct.pack("HL", nb, id(bpf)+36)
else:
bpfh = struct.pack("HI", nb, id(bpf)+20)
s.setsockopt(SOL_SOCKET, SO_ATTACH_FILTER, bpfh)
def set_promisc(s,iff,val=1):
mreq = struct.pack("IHH8s", get_if_index(iff), PACKET_MR_PROMISC, 0, "")
if val:
cmd = PACKET_ADD_MEMBERSHIP
else:
cmd = PACKET_DROP_MEMBERSHIP
s.setsockopt(SOL_PACKET, cmd, mreq)
def read_routes():
try:
f=open("/proc/net/route","r")
except IOError:
warning("Can't open /proc/net/route !")
return []
routes = []
s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
ifreq = ioctl(s, SIOCGIFADDR,struct.pack("16s16x",LOOPBACK_NAME))
addrfamily = struct.unpack("h",ifreq[16:18])[0]
if addrfamily == socket.AF_INET:
ifreq2 = ioctl(s, SIOCGIFNETMASK,struct.pack("16s16x",LOOPBACK_NAME))
msk = socket.ntohl(struct.unpack("I",ifreq2[20:24])[0])
dst = socket.ntohl(struct.unpack("I",ifreq[20:24])[0]) & msk
ifaddr = scapy.utils.inet_ntoa(ifreq[20:24])
routes.append((dst, msk, "0.0.0.0", LOOPBACK_NAME, ifaddr))
else:
warning("Interface lo: unkown address family (%i)"% addrfamily)
for l in f.readlines()[1:]:
iff,dst,gw,flags,x,x,x,msk,x,x,x = l.split()
flags = int(flags,16)
if flags & RTF_UP == 0:
continue
if flags & RTF_REJECT:
continue
try:
ifreq = ioctl(s, SIOCGIFADDR,struct.pack("16s16x",iff))
except IOError: # interface is present in routing tables but does not have any assigned IP
ifaddr="0.0.0.0"
else:
addrfamily = struct.unpack("h",ifreq[16:18])[0]
if addrfamily == socket.AF_INET:
ifaddr = scapy.utils.inet_ntoa(ifreq[20:24])
else:
warning("Interface %s: unkown address family (%i)"%(iff, addrfamily))
continue
routes.append((socket.htonl(long(dst,16))&0xffffffffL,
socket.htonl(long(msk,16))&0xffffffffL,
scapy.utils.inet_ntoa(struct.pack("I",long(gw,16))),
iff, ifaddr))
f.close()
return routes
############
### IPv6 ###
############
def in6_getifaddr():
"""
Returns a list of 3-tuples of the form (addr, scope, iface) where
'addr' is the address of scope 'scope' associated to the interface
'ifcace'.
This is the list of all addresses of all interfaces available on
the system.
"""
ret = []
try:
f = open("/proc/net/if_inet6","r")
except IOError, err:
return ret
l = f.readlines()
for i in l:
# addr, index, plen, scope, flags, ifname
tmp = i.split()
addr = struct.unpack('4s4s4s4s4s4s4s4s', tmp[0])
addr = scapy.utils6.in6_ptop(':'.join(addr))
ret.append((addr, int(tmp[3], 16), tmp[5])) # (addr, scope, iface)
return ret
def read_routes6():
try:
f = open("/proc/net/ipv6_route","r")
except IOError, err:
return []
# 1. destination network
# 2. destination prefix length
# 3. source network displayed
# 4. source prefix length
# 5. next hop
# 6. metric
# 7. reference counter (?!?)
# 8. use counter (?!?)
# 9. flags
# 10. device name
routes = []
def proc2r(p):
ret = struct.unpack('4s4s4s4s4s4s4s4s', p)
ret = ':'.join(ret)
return scapy.utils6.in6_ptop(ret)
lifaddr = in6_getifaddr()
for l in f.readlines():
d,dp,s,sp,nh,m,rc,us,fl,dev = l.split()
fl = int(fl, 16)
if fl & RTF_UP == 0:
continue
if fl & RTF_REJECT:
continue
d = proc2r(d) ; dp = int(dp, 16)
s = proc2r(s) ; sp = int(sp, 16)
nh = proc2r(nh)
cset = [] # candidate set (possible source addresses)
if dev == LOOPBACK_NAME:
if d == '::':
continue
cset = ['::1']
else:
devaddrs = filter(lambda x: x[2] == dev, lifaddr)
cset = scapy.utils6.construct_source_candidate_set(d, dp, devaddrs, LOOPBACK_NAME)
if len(cset) != 0:
routes.append((d, dp, nh, dev, cset))
f.close()
return routes
def get_if(iff,cmd):
s=socket.socket()
ifreq = ioctl(s, cmd, struct.pack("16s16x",iff))
s.close()
return ifreq
def get_if_index(iff):
return int(struct.unpack("I",get_if(iff, SIOCGIFINDEX)[16:20])[0])
if os.uname()[4] == 'x86_64':
def get_last_packet_timestamp(sock):
ts = ioctl(sock, SIOCGSTAMP, "1234567890123456")
s,us = struct.unpack("QQ",ts)
return s+us/1000000.0
else:
def get_last_packet_timestamp(sock):
ts = ioctl(sock, SIOCGSTAMP, "12345678")
s,us = struct.unpack("II",ts)
return s+us/1000000.0
def _flush_fd(fd):
if type(fd) is not int:
fd = fd.fileno()
while 1:
r,w,e = select([fd],[],[],0)
if r:
os.read(fd,MTU)
else:
break
class L3PacketSocket(SuperSocket):
desc = "read/write packets at layer 3 using Linux PF_PACKET sockets"
def __init__(self, type = ETH_P_ALL, filter=None, promisc=None, iface=None, nofilter=0):
self.type = type
self.ins = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(type))
self.ins.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 0)
_flush_fd(self.ins)
if iface:
self.ins.bind((iface, type))
if not nofilter:
if conf.except_filter:
if filter:
filter = "(%s) and not (%s)" % (filter, conf.except_filter)
else:
filter = "not (%s)" % conf.except_filter
if filter is not None:
attach_filter(self.ins, filter)
self.ins.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 2**30)
self.outs = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(type))
self.outs.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 2**30)
if promisc is None:
promisc = conf.promisc
self.promisc = promisc
if self.promisc:
if iface is None:
self.iff = get_if_list()
else:
if iface.__class__ is list:
self.iff = iface
else:
self.iff = [iface]
for i in self.iff:
set_promisc(self.ins, i)
def close(self):
if self.closed:
return
self.closed=1
if self.promisc:
for i in self.iff:
set_promisc(self.ins, i, 0)
SuperSocket.close(self)
def recv(self, x=MTU):
pkt, sa_ll = self.ins.recvfrom(x)
if sa_ll[2] == socket.PACKET_OUTGOING:
return None
if sa_ll[3] in conf.l2types:
cls = conf.l2types[sa_ll[3]]
lvl = 2
elif sa_ll[1] in conf.l3types:
cls = conf.l3types[sa_ll[1]]
lvl = 3
else:
cls = conf.default_l2
warning("Unable to guess type (interface=%s protocol=%#x family=%i). Using %s" % (sa_ll[0],sa_ll[1],sa_ll[3],cls.name))
lvl = 2
try:
pkt = cls(pkt)
except KeyboardInterrupt:
raise
except:
if conf.debug_dissector:
raise
pkt = conf.raw_layer(pkt)
if lvl == 2:
pkt = pkt.payload
if pkt is not None:
pkt.time = get_last_packet_timestamp(self.ins)
return pkt
def send(self, x):
iff,a,gw = x.route()
if iff is None:
iff = conf.iface
sdto = (iff, self.type)
self.outs.bind(sdto)
sn = self.outs.getsockname()
ll = lambda x:x
if type(x) in conf.l3types:
sdto = (iff, conf.l3types[type(x)])
if sn[3] in conf.l2types:
ll = lambda x:conf.l2types[sn[3]]()/x
try:
sx = str(ll(x))
x.sent_time = time.time()
self.outs.sendto(sx, sdto)
except socket.error,msg:
x.sent_time = time.time() # bad approximation
if conf.auto_fragment and msg[0] == 90:
for p in x.fragment():
self.outs.sendto(str(ll(p)), sdto)
else:
raise
class L2Socket(SuperSocket):
desc = "read/write packets at layer 2 using Linux PF_PACKET sockets"
def __init__(self, iface = None, type = ETH_P_ALL, filter=None, nofilter=0):
if iface is None:
iface = conf.iface
self.ins = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(type))
self.ins.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 0)
_flush_fd(self.ins)
if not nofilter:
if conf.except_filter:
if filter:
filter = "(%s) and not (%s)" % (filter, conf.except_filter)
else:
filter = "not (%s)" % conf.except_filter
if filter is not None:
attach_filter(self.ins, filter)
self.ins.bind((iface, type))
self.ins.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 2**30)
self.outs = self.ins
self.outs.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 2**30)
sa_ll = self.outs.getsockname()
if sa_ll[3] in conf.l2types:
self.LL = conf.l2types[sa_ll[3]]
elif sa_ll[1] in conf.l3types:
self.LL = conf.l3types[sa_ll[1]]
else:
self.LL = conf.default_l2
warning("Unable to guess type (interface=%s protocol=%#x family=%i). Using %s" % (sa_ll[0],sa_ll[1],sa_ll[3],self.LL.name))
def recv(self, x=MTU):
pkt, sa_ll = self.ins.recvfrom(x)
if sa_ll[2] == socket.PACKET_OUTGOING:
return None
try:
q = self.LL(pkt)
except KeyboardInterrupt:
raise
except:
if conf.debug_dissector:
raise
q = conf.raw_layer(pkt)
q.time = get_last_packet_timestamp(self.ins)
return q
class L2ListenSocket(SuperSocket):
desc = "read packets at layer 2 using Linux PF_PACKET sockets"
def __init__(self, iface = None, type = ETH_P_ALL, promisc=None, filter=None, nofilter=0):
self.type = type
self.outs = None
self.ins = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(type))
self.ins.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 0)
_flush_fd(self.ins)
if iface is not None:
self.ins.bind((iface, type))
if not nofilter:
if conf.except_filter:
if filter:
filter = "(%s) and not (%s)" % (filter, conf.except_filter)
else:
filter = "not (%s)" % conf.except_filter
if filter is not None:
attach_filter(self.ins, filter)
if promisc is None:
promisc = conf.sniff_promisc
self.promisc = promisc
if iface is None:
self.iff = get_if_list()
else:
if iface.__class__ is list:
self.iff = iface
else:
self.iff = [iface]
if self.promisc:
for i in self.iff:
set_promisc(self.ins, i)
self.ins.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 2**30)
def close(self):
if self.promisc:
for i in self.iff:
set_promisc(self.ins, i, 0)
SuperSocket.close(self)
def recv(self, x=MTU):
pkt, sa_ll = self.ins.recvfrom(x)
if sa_ll[3] in conf.l2types :
cls = conf.l2types[sa_ll[3]]
elif sa_ll[1] in conf.l3types:
cls = conf.l3types[sa_ll[1]]
else:
cls = conf.default_l2
warning("Unable to guess type (interface=%s protocol=%#x family=%i). Using %s" % (sa_ll[0],sa_ll[1],sa_ll[3],cls.name))
try:
pkt = cls(pkt)
except KeyboardInterrupt:
raise
except:
if conf.debug_dissector:
raise
pkt = conf.raw_layer(pkt)
pkt.time = get_last_packet_timestamp(self.ins)
return pkt
def send(self, x):
raise Scapy_Exception("Can't send anything with L2ListenSocket")
conf.L3socket = L3PacketSocket
conf.L2socket = L2Socket
conf.L2listen = L2ListenSocket
conf.iface = get_working_if()